This invention relates to concrete forming systems and, more particularly, to an improved tie member for holding and maintaining the sidewalls of a concrete form in their desired relationship while resisting static and hydraulic loads acting thereon.
The use of polymeric foam concrete forms in the construction industry is known. These forms present a pair of sidewalls with vertical and/or horizontal cavities formed therebetween. Upon filling the cavities with concrete and subsequent curing, a concrete wall is presented between the insulating walls. The forms have complementary mating elements for joining the forms in a side-by-side and/or over/under relationship. Examples of such concrete forms are shown in various patents including U.S. Pat. No. 3,788,020 to Gregori.
One problem with use of the forms is the maintenance of the sidewalls of the forms in their original longitudinal and/or lateral relationships. As the poured concrete imparts a dynamic, hydraulic load on the sidewalls, the sidewalls tend to displace which can cause a separation or "blow out" of adjacent forms. Thus, it is desirable to preclude such separation particularly along the horizontal and vertical joints formed between adjacent forms. Tension members as shown in the Gregori U.S. Pat. No. 3,788,020 and the DeLozier U.S. Pat. No. 4,223,501 have been used to preclude such displacement. Basically, these tension members are in the form of a transverse connecting member made of a wire mesh or the like which extends between the sidewalls of each concrete form.
Also during transport the forms are stacked on their sidewalls one atop the other. The weight of the overlying forms may displace the sidewalls of the underlying forms. If so, the forms are difficult to easily connect due to the various distances between the sidewalls of the forms. Thus, preparation time is increased.
The known ties extending between the form sidewalls may not effectively resist static and dynamic loads acting thereon. As the form sidewalls may shift in lateral and/or longitudinal directions during transport and concrete pouring, it is desirable to provide a form tie which precludes such sidewall displacement.
In response thereto we have invented a form tie for use in a concrete forming system generally comprising a transverse web made of an expanded metal or the like. Located at the opposed ends of the web are first flange walls embedded within the form sidewalls. At the free end of each first flange wall is a supplemental web normally extending toward the outside surface of each sidewall. A parallel flange wall then extends from the free end of this supplemental web and towards the major web. An anchor wall at the end of each second flange wall further grips the surrounding foam of the sidewalls. The configuration of the form tie effectively stiffens the entire tie which resists external static and dynamic loads imposed on the form. In turn, the form retains its original shape such that the desired modularity among the forms is maintained. As the allowable load carrying capabilities of each form is increased, greater flexibility of form use results. As such, the height of form courses may be increased before initiating concrete pouring therein.
It is therefore a general object of this invention to provide a form tie for a concrete form which effectively resists static and dynamic loads acting thereon.
Another object of this invention is to provide a form tie, as aforesaid, which is integrated into the form proper during the molding process.
Another object of this invention is to provide a form tie, as aforesaid, which presents structure embedded in the form wall to preclude lateral and longitudinal shifting of the form walls during transport and/or use.
A more particular object of this invention is to provide a form tie, as aforesaid, which effectively grips the surrounding form material.
A still further particular object of this invention is to provide a form tie, as aforesaid, which does not interfere with the flow of concrete between the form sidewalls.
Another particular object of this invention is to provide a form tie, as aforesaid, which is easily formed from expanded metal, fiberglass or other suitable materials.
Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings, wherein is set forth by way of illustration and example, an embodiment of this invention.